Large banks, hedge funds and private investors hungry for new and lucrative opportunities are bankrolling other people’s lawsuits, pumping hundreds of millions of dollars into medical malpractice claims, divorce battles and class actions against corporations — all in the hope of sharing in the potential winnings.

The loans are propelling large and prominent cases. Lenders including Counsel Financial, a Buffalo company financed by Citigroup, provided $35 million for the lawsuits brought by ground zero workers that were settled tentatively in June for $712.5 million. The lenders earned about $11 million.